/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: DocumentCall.java,v 1.2.4.1 2005/09/01 14:10:13 pvedula Exp $
 */

package com.sun.org.apache.xalan.internal.xsltc.compiler;

import java.util.Vector;

import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
import com.sun.org.apache.bcel.internal.generic.GETFIELD;
import com.sun.org.apache.bcel.internal.generic.INVOKEINTERFACE;
import com.sun.org.apache.bcel.internal.generic.INVOKESTATIC;
import com.sun.org.apache.bcel.internal.generic.InstructionList;
import com.sun.org.apache.bcel.internal.generic.PUSH;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMsg;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;

/**
 * @author Jacek Ambroziak
 * @author Morten Jorgensen
 */
final class DocumentCall extends FunctionCall {

  private Expression _arg1 = null;
  private Expression _arg2 = null;
  private Type _arg1Type;

  /**
   * Default function call constructor
   */
  public DocumentCall(QName fname, Vector arguments) {
    super(fname, arguments);
  }

  /**
   * Type checks the arguments passed to the document() function. The first
   * argument can be any type (we must cast it to a string) and contains the
   * URI of the document
   */
  public Type typeCheck(SymbolTable stable) throws TypeCheckError {
    // At least one argument - two at most
    final int ac = argumentCount();
    if ((ac < 1) || (ac > 2)) {
      ErrorMsg msg = new ErrorMsg(ErrorMsg.ILLEGAL_ARG_ERR, this);
      throw new TypeCheckError(msg);
    }
    if (getStylesheet() == null) {
      ErrorMsg msg = new ErrorMsg(ErrorMsg.ILLEGAL_ARG_ERR, this);
      throw new TypeCheckError(msg);
    }

    // Parse the first argument
    _arg1 = argument(0);

    if (_arg1 == null) {// should not happened
      ErrorMsg msg = new ErrorMsg(ErrorMsg.DOCUMENT_ARG_ERR, this);
      throw new TypeCheckError(msg);
    }

    _arg1Type = _arg1.typeCheck(stable);
    if ((_arg1Type != Type.NodeSet) && (_arg1Type != Type.String)) {
      _arg1 = new CastExpr(_arg1, Type.String);
    }

    // Parse the second argument
    if (ac == 2) {
      _arg2 = argument(1);

      if (_arg2 == null) {// should not happened
        ErrorMsg msg = new ErrorMsg(ErrorMsg.DOCUMENT_ARG_ERR, this);
        throw new TypeCheckError(msg);
      }

      final Type arg2Type = _arg2.typeCheck(stable);

      if (arg2Type.identicalTo(Type.Node)) {
        _arg2 = new CastExpr(_arg2, Type.NodeSet);
      } else if (arg2Type.identicalTo(Type.NodeSet)) {
        // falls through
      } else {
        ErrorMsg msg = new ErrorMsg(ErrorMsg.DOCUMENT_ARG_ERR, this);
        throw new TypeCheckError(msg);
      }
    }

    return _type = Type.NodeSet;
  }

  /**
   * Translates the document() function call to a call to LoadDocument()'s
   * static method document().
   */
  public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
    final ConstantPoolGen cpg = classGen.getConstantPool();
    final InstructionList il = methodGen.getInstructionList();
    final int ac = argumentCount();

    final int domField = cpg.addFieldref(classGen.getClassName(),
        DOM_FIELD,
        DOM_INTF_SIG);

    String docParamList = null;
    if (ac == 1) {
      // documentF(Object,String,AbstractTranslet,DOM)
      docParamList = "(" + OBJECT_SIG + STRING_SIG + TRANSLET_SIG + DOM_INTF_SIG
          + ")" + NODE_ITERATOR_SIG;
    } else { //ac == 2; ac < 1 or as >2  was tested in typeChec()
      // documentF(Object,DTMAxisIterator,String,AbstractTranslet,DOM)
      docParamList = "(" + OBJECT_SIG + NODE_ITERATOR_SIG + STRING_SIG
          + TRANSLET_SIG + DOM_INTF_SIG + ")" + NODE_ITERATOR_SIG;
    }
    final int docIdx = cpg.addMethodref(LOAD_DOCUMENT_CLASS, "documentF",
        docParamList);

    // The URI can be either a node-set or something else cast to a string
    _arg1.translate(classGen, methodGen);
    if (_arg1Type == Type.NodeSet) {
      _arg1.startIterator(classGen, methodGen);
    }

    if (ac == 2) {
      //_arg2 == null was tested in typeChec()
      _arg2.translate(classGen, methodGen);
      _arg2.startIterator(classGen, methodGen);
    }

    // Feck the rest of the parameters on the stack
    il.append(new PUSH(cpg, getStylesheet().getSystemId()));
    il.append(classGen.loadTranslet());
    il.append(DUP);
    il.append(new GETFIELD(domField));
    il.append(new INVOKESTATIC(docIdx));
  }

}
